Companies that cut workers' hours to avoid paying benefits may put themselves on the wrong side of the law.

The Obama administration's announcement this month that it will delay implementation of a key provision of the Affordable Care Act – the requirement that larger employers provide affordable insurance to workers logging 30-plus hours per week – gives firms more time to make key decisions about how they will comply.

The choice for organizations with many hourly workers has generally come down to a few options, among them: extend benefits to more employees and swallow the cost; fail to comply and instead pay a penalty for...